A method of renewing worn tread portions of reinforced rubber tracks which is particularly applicable to the heavy reinforced tracks used on mechanical diggers, mobile cranes and other vehicles, such method involving placing a previously buffed track circumferentially around a correspondingly dimensioned holding ring (4) so that the metal lugs (3) of the track are supported by the holding ring (4); inserting two correspondingly shaped rings (8), one on each side of the row of lugs (3), so as to conform to the space between the track and the holding ring; applying pre-vulcanized tread (5) to the track with a layer of unvulcanised rubber between the tread and the track; surrounding the thus-formed assembly with a generally airtight envelope; creating a vacuum within the envelope (9) and vulcanising the said unvulcanised rubber so as to bond the tread (5) to the track (1).